1231399 has 4 divisors (see below), whose sum is σ = 1326136. Its totient is φ = 1136664.

The previous prime is 1231387. The next prime is 1231411. The reversal of 1231399 is 9931321.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1231387) and next prime (1231411).

It is a cyclic number.

It is not a de Polignac number, because 1231399 - 2¹¹ = 1229351 is a prime.

It is an Ulam number.

It is a Duffinian number.

1231399 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47349 + ... + 47374.

It is an arithmetic number, because the mean of its divisors is an integer number (331534).

2^1231399 is an apocalyptic number.

1231399 is a deficient number, since it is larger than the sum of its proper divisors (94737).

1231399 is an equidigital number, since it uses as much as digits as its factorization.

1231399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94736.

The product of its digits is 1458, while the sum is 28.

The square root of 1231399 is about 1109.6841893079. The cubic root of 1231399 is about 107.1847334297.

The spelling of 1231399 in words is "one million, two hundred thirty-one thousand, three hundred ninety-nine".